Heating means



6 Sheets-Sheet 2 s s R wup w Nef. R wg m A fw. e

Aug. 3, 1937-. H. GEORGE er AL HEATING MEANS Filed Jan. 27, 1934 AUS 3,1937 H. GEoRGE E1' An. 2,089,022

HEATING MEANS Filed Jan. 27, 1934 6 Sheets-Sheet 5 64s raw DELPEc/J Aug.3, 1937. H. GEoRGEE-r AL HEATING MEANS Filed Jan. 2'7, 1934 HV i I 7Hl... M8

6 Sheets-Sheet 4 INVEN ORS /E/ve/ sages ATTORNEYS Aug.'3, 1937. H. GERGEEr L 2,089,022

HEATING MEANS Filed Jan. 27, '1954 e sheets-sheet 5 276 2 73 /275 Y 27M296 296 277 K v l l 3M .322 v 258 272 I I l 25% 27g l l fr l Ill ...l251 266 l f2 /f/f//f/ flfff, f 26/ 3 25 313 00 a 272 2 276 376 301 2272?/ j 277 E Zy .27d E f I L 17 o 296 3/2 641287 I '263222 j 22d/iii i?,Y 26? 277 250 26o 26 2a@ L 292 252 Maig@ 222 o 26 .2x65 I 2W" o l/f/ve/G'N QRS ATTORNEYS Aug. 3, 1937.

H. GEORGE ET AL,

HEATING MEANS Filed Jan. '27. 1954 6 Sheets-Sheet 6 4Patented Aug.- 3,1937 UNITED "STATI-:s

PATENT oFFicF.

2,089,022 HEATING MEANS Chimiques de Saint- Paris, France l Gobain,Chauny & Cirey,

Application January 27, 1934, Serial No. 708,618 In France January 30,1933 9 Claims.

This invention refers to heating means and relates more particularly toelectrical furnaces for heating, fusing and/or casting articles made ofsubstances having a high melting point, said furnaces being preferablyused for the melting of refractory material, such as quartz.

In our copending patent application relating to Electrical heating,Serial Number 648,996 le'd December 27th, 1932, an electrical furnace isdescribed, which comprises a heating element consisting of a carbonrodand surrounded by a container which is situated within the zone ofheat radiated by the heating element and which is movable with respectto this element. `A gaseous medium may be introduced into the furnaceand allowed 'to flow between Vthe heating element and the walls of thecontainer.

An object of the present invention is to provide certain improvements infurnaces of this type to increase their output and their eil` ciency.

A considerable amount of heat is lost in rotatable electrical furnacesknown in prior art, particularly at the two ends of the cylindrical con#tainer. Practical experience has shown that in some instances theelectrical contact between aterminal connected with a source ofelectrical energyand the heating element is liable to be interrupted inthe course of operation of the furnace.

It was found that the gas introduced into a rotatable electrical furnacewas not utilizedto the greatest possible extent because of certainconstructional defects of such furnaces and also because no means wereprovided Vfor reversing the direction of ow of the gas passing throughthe furnace.

Other drawbacks of electrical furnaces used in prior .art consist inthat it was necessary to use entirely new supporting means when acontainer havinga different diameter was to' be employed and also inthat a heating element situated in the middle of a container sometimesfailed to radiate an amount of heat which was suiiicient for themanufacture of hollow articles having a large diameter and walls of avariable thickness.

It was also found that furnaces, the fusing mnes of which must be devoidof contact with the surrounding-atmosphere do not operate emciently in anumber of instances due to the lack of proper connecting meansbetweenthe electrical terminals and thel rotatable parts ci the furnaces.

The use of a single heating rod in a rotatable furnace is oftenimpractical, particularly when a poly-phase electrical current isavailable for heating purposes.

Another object of the present invention is to compensate for the higherlosses in heat at the end sections of a yfurnace by increasing theamount of heat generated by a heating element in these sections of thefurnace.

A further object is the provision of a furnace havingA resilient meanswhich are adapted to maintain a steady contactbetween the terminals andthe heating element in spite of the movements of the various parts of afurnace in the course of the heating or fusing process.

Still another object is the provision of a furnace having means forregulating the flow of a gas therein, said furnace being also providedwith a device adapted to reverse the flow of the gas within the furnace.

Still further object is the provision of means for supporting containershaving various dimensions in such a way, that the axis of rotation ofthesecontainers is always maintained at the same level from the floor ofthe Workshop irrespective of thefsize of the containers.

Another` object of the invention is the provision of a furnace adaptedto manufacture hollow bodies having large diameters and Walls of avarying thickness.

Still another object is to provide for a better connection betweentheterminals and the rotary containers of furnaces the zone of fusion ofwhich must be devoid of communication with the surrounding atmosphere.

A further object is the provision of a heating element which can beheated by a three-phase electrical current.

The above and other objects of the present invention may be realizedthrough the provision of an electrical furnace or furnaces whichcomprise a vl'ieating rod, the end portions of which have across-section which is smaller than that of the middle of the rod. Aspring or other resilient member is used for interconnecting me'-chanically but not electrically one of the electrical current terminalswith the main body oi' the rotatable furnace; the ends of the rotatablecontainer and the supports carrying the ends of the heating rod carrydiscs or plates preferably made of graphite or amorphous carbon and usedto direct the iiow of a gas through the furnace. Fans or other suitableVentilating devices are used for reversing the direction of flow of thegas at suitable intervals. The rotatable container is carried by rollersmounted on adjustable supports, so that when a container having acertain diameter is replaced by a container having a larger or a smallerdiameter, the position of the rollers may be adjusted in such a way,that the central axis of the new container occupies the samev positionasthe central axis of the previously used container. Heating rods of largefurnaces are placed at a certain distance from and parallel to thecentral axis of rotation of the container, and are carried by meansadapted to revolve the heating rods with a variable velocity within thecontainers. In furnaces which must have a hermetic-ally closed fusingzone, suitable sealing means are provided between the terminals and thecontainer, 'which-is rotatable in two different directions. To enablethe use of a three-phase current for the heating of the electricalheating element, this element is made of three separate rods which areelectrically joined in a star-connection and are carried by a movablesupport. A refractory granulated material, such as quartz, is placed inthe interior of the rotary furnace and is pressed against the inner sidewalls of the furnace by centrifugal forces developed in the course -ofthe rotationthereof.

The invention will appear more clearly from the following detaileddescription when taken in connection with the accompanying drawingsiowing preferred embodiments of the inventive In the drawings:

.Figure 1 shows an electrical furnace in side elevation, and partly inaxial-section.

Figure 2 shows a portion of the same furnace in vertical axial-sectionand on a larger scale.

Figure 3 is a section'along the line 3-3 of Fig- Figure 4 is a sectionalong the line 3 4 of Figure Figure 8 is a section along the line 3--3of Fig- Vurel.

Figure 'I shows a furnace having a hermetically closed fusing zone inaxial-section and partly in side elevation.

liigure'I 8 is a section along the line 3-3 of Figl'igure.I 3 is asection along the line 3--3 of Figure Figure 10 shows on a larger scaleand in vertical axial-section a part of the furnace illustrated inFigure '1. l

`Figure 11 is a section along the line ll--II` of Figure' 10. l

Figure 12 shows another part of the furnace illustrated in Figure '1 ona larger scale and in vertical axial-section. i Figure 13 is a sectionalong the line 13-I3 of Figure 12. y

Figure 14 is a section along the line lil-Il of llsure 12. l

'- Figure 15 shows partly in vertical section and partly in sideelevation a furnace used for the manufacture ofV large hollow articles.

Figure 13 shows on a larger scale and in vertical cross-section a partof the furnace illustrated in ligure 15. Y f

Figure i7 is s section along the line I1.-i1 of Figure 18.

Figure 13 shows e furnace of a somewhat different type in verticalsection, some parte bein! shown in side-elevation.

mmmmwsmemunlmentwmiia connection with the furnace illustrated in Figure18.

Figure 20 is a section alongthe line 2li-2U of Figure 18.

Figure 2l shows on a larger scale and in vertical section a: part of thedevice illustrated in Figure 18. Y

Figure 22 is a section through a part of the heating element, shown inFigure 19, on a larger scale.

The furnace illustrated in Figures 1 to 6 ol the drawings comprises aheating rod or resistance 25 which is made of carbon and has the shapeof a cylinder. The heating element 25 is provided with a hole 2B boredalong its central axis and with longitudinal grooves 21 which are shownmore clearly in Figures 2 and 4.

The heating element 25 has two conical ends 28 and 29 (Fig. 2); a largeramount of heat is radiated by these conical ends than by the maincylindrical portionof the heating element, The end 23 is Situated Withina corresponding cavity formed in a support or cylinder 30 which is madeof graphite and which is provided with exterior screw threads 3|. Anabutment 32 is formed on the exterior surface of the cylinder 33 and isused for adjusting the position of the resistance 25 according to itslength.

The opposite end 23 of the resistance 25 is situated in a cavity formedin a similar cylinder 33 which is made of graphiteand is provided withexterior screw threads 3l. 'I'he cylinder 33 is also provided with anabutment 35 which serves for the same purpose as the abutment 32,namely, for adjusting the position of the heating element within thefurnace.

A conical sleeve 36 is provided with interior screw threads whichcorrespond to the screw threads 3| so that the cylinder 30 may bescrewed into the interior of the sleeve 36. A similar sleeve 31 isarranged ati the opposite end of the furnace and surrounds the cylinder33 which is screwed into the sleeve 31 by means of screw threads 34. Theksleeves 36 and 31 are both made of graphite.

Two large plates 33 and 33, which are made of amorphous carbon, aresituated on opposite sides of the furnace. Both plates are poorconductors of heat so that the heat radiated by the resistance 23 cannoteasily escape into the exterior. The plate 33 is provided with anopening I3 a part of which is conical in shape so that the sleeve 35 canbe fitted into the plate 33. The plate 33 is provided with a similaropening 4I andcarries the sleeve 31.

A stopper l2 provided with screw threads 3 may be screwed into the plate33 to close the opening l0. A similar stopper 4| is situated at theopposite end of the furnace and is provided with screw threads l5. The`stopper 44 is screwed into the plate 33 and is used for closing theopening 4I formed in the plate 33.

'Ihe plate 33 is surrounded by a metallic casing I3 which is connectedat I1 with a source of electrical energy not shown in the drawings. Theplate 33 is surrounded and carried by a similar metallic casing 43 whichis connected at 43 tothe samesource of electrical energy.

A radial opening Il is formed in the metallic casing 43 and the plate33. The opening 50 Joins the central opening Il and is used for theinsertion of means for adjusting the heating element 23 into the'furnace. or to remove itl out of the furnace.

A carbon rod 5I is situated within the opening 50 and is provided with alower conicallend 23 which may come in contact with the resistance 25and which may be used to adjust the position of this resistance. Thecarbon rod 5| is connected by a narrower portion 52 with an upperportion 53, a part of which is provided with screw threads meshing withcorresponding screw threads formed in the metal casing 46.

A handle 54 is used for moving the rod 5| up and down within the opening50 when it is necessary to adjust the resistance 25 into the furnace orto remove it out of the furnace. -The handle 54 and the adjacent part ofthe member 53 are, when necessary, electrically insulated fromy themetal casing 46 by any suitable means not shown in the drawings.

A disc 55 made of graphite is situated at a certain distance from theplate'38 and iS used as a connection between the metallic casing 46 andthe sleeve 56 which surrounds a portion of the resistance 25 withoutcoming in contact with the resistance.

A similar graphite disc 51 is placed at the opposite side of the furnaceand supports a sleeve 58 around another portion of the resistance 25.

The sleeve 56 carries a number of rings 59 and 60 made 'of graphite andhaving different diameters; Similar rings 6I and 62 are carried by thesleeve 58.

The resistance 25 is surrounded by a rotary casing 63 containing thematerial 64 which is to be fused in the furnace.

An annular plate 65 which is made of a heat resisting material is usedfor closing one end of the casing 63. A similar plate 66 made preferablyof the same material is situated at the opposite end of the furnace.

A pair of. rings 61 and 68 consisting of graphite are carried by theplate 65. Similar rings 69 and 10 are carried by the plate 66.

A metallic annular ange 1I is carried by the casing63 and is connectedthrough the'medium of an annular member 12 with a screen or ring 13.

Another annular plate 14 which is made of heat resisting material issituated between the plate 65 and the screen 13.

A similar device is provided at the opposite end of the furnace. Anannular fiange 15 is carried by the casing 63 and supports through themedium of a member 16 a screen 11, which in its turn serves as a supportfor the plate 16 made of a heat risting material.

The disc 55 is situated at a certain distance from the flange 1| so thata space 19 is formed between these two members.

The fianges 1| and 15 are provided with annular projecting portions and8|, respectively, the portion 80 of the flange 1I closing partly theopening 8Ia of a hollow casing 62 shown in Fig ure 1, while the portion8| of the flange 15 closes partly the opening 81.

As shown in Figures l and 6 of the drawings, the casing 32 isprovided'with walls 83 having openings 84, which may be closed by meansof shutters 85.

At the opposite end ofV the furnace there is a casing 86 having anopening 81 which is partly closed by the portion 8| of the flange 15.The opposite walls I|4 of the casing 86 are provided with openings 88which may be closed by means v of shutters 89.

A fan 90 is driven by a motor 9| carried by an arm 92 which is connectedwith the wall 63 of the casing 82.

A similar fan 93 is situated at the opposite end of the furnace and isdriven by a motor 94 which is carried by an arm 95 attached to the walllI I4 of the casing 86. The motors 9| and 94 are provided with suitableswitches |48 and |49, respectively.

When the fan 93 is being operated, the shutters 85 at the opposite endof the furnace may be placedl in such a way that they partly close thcopenings 84 with the result that the fan 9U is not affected by thecurrent of air and gases produced by the fan 93.

The fan 93 produces a current of air within the chamber 96 surrounded bythe casing 86. This current of air passes through the opening 81 andthrough the space 91 formed between the disc 51 (Fig. 2)v and the flange15. Hot gases flow through the space 98 formed between they rings 6| and62 on one side and the members 11, 18, 10, a'nd 69 on the other side(Fig. 2) and 'f penetrate into the interior of thecasing 63.

The heated gases leaving the interior of the casing 63 pass through thespace 99 formedbetween the rings 59 and 60 on the one hand, and..y

the members 61, 68, 14, and 13 on the other hand. These gases leave thefurnace through the space 19.

As shown in Figure 1, the metal casing 46 is carried by two insulatingsupports |00 and I0i, which are carried by the casing 82.

The metal casing 48 is carried by the supports I 82 and |03, which aresupported by the casing 86.

The casing 82 is carried by supports |64 and I 05, which are rigidlyconnected with and carried by a carriage |06. Two guide rollers |01 and|68 are connected with each other by an arm |09, which is carried by asupport ||,0. Tworollers ||I and ||2 are situated on the opposite 'sideof the carriagev |06 and are rotatably mounted in an arm ||3. Thearm ||3is rigidly connected with the support ||0, which also carries an Lshaped iron |I5 and a finger IIB.

Due to this arrangement, the carriage |06 is movable in the direction ofthe longitudinal axis of the furnace along the four rollers |01, |08, II I, and II2. Since the casings 46 and 82 are rigidly connected with thecarriage |06; by the supports |00, |0I, |04, and |05, these casingsalong with the parts carried by these -casings may be moved in a,direction towards and away from the Casin" 63, when it is necessary toinsert the material 64 into the interior of the furnace, or to remove itfrom this furnace, or when it is necessary to replace the resistance 25by a new one.

When the melting process has been completed, the carriage |06 is freedby separating the spring II1 from the fixed-finger ||6. Then thecarriage |06 is moved away from the furnace aleng with all the partscarried by the carriage, thereby withdrawing the resistance 25 from theinterior of the furnace. After the solidification of the molten article,the ange 1| carried by the casing 63 is taken off, and then the rings 61and 68. the Plates 65 and 14, the screen 13 and the member l 12 areremoved. Then the cast article can be easily removed. due to theprovision of a iayer of comminuted substance which has not been moltenbetween the cast'article and the casing 69.

The support ||0 is connected with the main foundation, which is notshown in the drawings.

Since the end 28 of the resistance 25 is carried by a cylinder 32, whichis movable along with the casing 48 and the carriage |88, the spring||1, which tends to maintain the casing 48 and other members connectedwith this casing at a certain distance from the casing 82, prevents theend 28 of the resistance 25 from falling out of the cylinder 32;otherwise the end 28 and the cylinder 32 could easily becomedisconnected due to the fact that the carriage |08 is movable along therollers |01, |08, and ||2.

The support carries a plate ||8, which is pivotally connected with thesupport |I0 at H9. Another support |20 is situated at a close distancelfrom the support ||0, as shown in Figure 5, and is connected with asimilar plate |2| by means of a pivot |22. The plate ||8 supports ashaft |23, while the plate |2| supports a shaft |24. A pair of rollers|25 and |28 are mounted on the shaft |23, while a similar pair ofrollers |21, only one of which is shown in the drawings, are mounted onthe shaft |24.

As shown in Figure 5. the plate ||8 is provided with several openings|28, while the plate |2| is provided with similar openings |20. Abentarm |20 is carried by the support ||0 and is provided with anopening |2|, which is of the same size as any one of the openings |28. Asimilar arm |22 is rigidly connected with the support |20 and isprovided with an opening |82 of the same size as any one of the openings|28.

The casing 82 is rigidly connected with a ring` |24', which is incontact with and supported by the two rollers |25 and |21. A similarring |25 is situated at the opposite end of the casing 82 and issupported by another pair of rollers |25 and |21. The right-hand ends ofthe shafts |22 and |24 (looking in the direction of Figure `1) arecarried by two plates |28, only one of which is shown in the drawings.The plates |28 are pivotally mounted at |21 in the supports |28.

An annular member |89, which is rigidly connected withthe casing 82 isused for rotating the casing by any suitable means such as a geartransmission |40, which is driven by amotor |4|.

The device shown in Figures i and provides for the use of casings ofvarious diameters without the necessity of changing the position of theheating element 25. The plates ||8 and |2| are maintained in theposition shown in Figure 5 through the use of' a pair of pins, one oiwhich passes through one ot the openings |28 formed in the plate H8 andthrough the opening |2|; the other pin passes through one of theopenings |29 formed in the plate |2|, and through the opening |22 formedin the arm |22. i

If it is desired to use a different casing having a larger diameter, thepins are withdrawn from the openings, the plates ||0 and |2| are movedin the direction of the arrows shown in Figure 5 l and then one of thepins is again inserted into a different one of the openings |28 and theopening |2|. Another pin is'inserted in a similar manner through anotheropening |28 .and through the opening |22.

Due to this arrangement, the rollers |25 and |21 may be movedaway fromeach other so that a casing having a larger diameter may be substitutedfor the casing 82.A The largest casing which can be used'with theconstruction illusl trated in,4 Figure 5, is shown by broken lines inthe drawings.

To operate the furnace, the carriage |88 is first moved to the left(looking in the direction o! Figure 1). to permit the' insertion of thenieuwe end cover nl. which is preferably made ot sheet metal surfusiblematerial 84 into lthe interior of the casing 82. 'I'he motor |4| is thenstarted and rotates by means of the transmission |40 the annular member|28, the casing 82 and the members 84 to 18-carried by the casing 82.When the material to be fused has been inserted into the casing 82 thecarriage is moved into the position `support 38, 'the cylinder 20, theresistance 25,

the cylinder 23, the conical support 21, the plate 29 and the casing 48.

The furnace illustrated in Figures 'l to 14 of the drawings comprises aheating rod or electrical resistance |50, the end |5| of which isprovided with screw threads, as shown in Figure 10. The opposite end |52of the resistance |50l is conical in shape, as'shown in Figure 12. l

The end |5| of the resistance |50 is screwed into a threaded borehole,|52 formed in a support |54, which consists of amorphous carbon.(Figure The opposite end of the resistance |50 is supported in a cavityformed in a block |55, which is also made of amorphous carbon (Figure12).

A part of the block |54 is slightly conical in shape and is carried by asleeve |58. 'I'he block |55 is supported by a similar sleeve |51. 130th.sleeves are conductors ot electricity. A meoilic casing |58 sourroundson three sides .ook |58 and carries a metallic terminal which may beconnected to any suitable source of electrical energy not shown in thedrawings.

As shown in Figure 12, a metallic casing |80 surrounds the sleeve |51andis connected with one of the ends of an elongated tube |8I. The tube|8|, which is made of a conducting material carries at its opposite endaplate |82, which is firmly connected with another terminal |82.

A water jacket |84 (Figure l0) surrounds the casing |58 and carries twopipes |88 and |88, one of which serves as an inlet for the water.

'The water circulates between the casing |58 and layer |10. The conicalend cover |88 is rigidlyconnected with the cylindrical casing |88 byrivets or -other suitable means.`

A Jacket |12 shown in Figure 12, is carried by Vthe metallic casing |88and is connected with two pipes |12 and |14, which project into the in-'e terior o! the tube |8| and which pass through suitable openingsformed in the plate |82. The pipes |12 and, |14 are used for thecirculation of a cooling medium such as water, used for coolinlthemetsilic' casing |88.

As shown more clearly in Figure 1, the cylindrical casing |88 is rigidlyconnected with s A hollow casing |18.

attached to the tube ll aosaoge 5 rounds the water jacket |12. Africtional sealing ring |11 (Figures 'I and 12) made of an insulatingmaterial is interposed between the casing |18 and the end cover. |15.The casing |16 is carried by a support 243 and carries a tubular sleeveor guiding member |18 which is provided with flanges |19, rigidly'connected with the casing |16.

Due to this arrangement, the resistance |50 and its ends are movable toa certain extent within the casing |69 in the direction of itslongitudinal axis. This axial movement is possible because the tube |6|,is movable with respect to the sleeve |18.

The jacket |84 connected with the metallic casing |58 is movable alongwith the block |5, the resistance |50, the block |55, the sleeve |51,(Figure 12) the casing |60 and the tube |6|.

The furnace is provided with resilient means for maintaining the propercontact between the end |52 of the 'resistance |50 and the block. i55.These means comprise a bolt |80, one end of which is rigidly connectedwith the casing iid. The bolt. |50 has screw threads |8| and carries awinged nut 582 as well as a washer |83.

` A coiled spring |94 surrounds the boit til@ and is in Contact at oneof its ends with the washer |523. The opposite end of the spring pressesagainst the bifurcated end |85 of a lever (Figure 14). rllhe lever |96is carried et its lower end by a hool; |81, the opposite end of which isrigidly connected with the casing liti. The middle E88 of the lever 85.is somewhat bent and surrounds an insulating rod |59, which is nly andwhich n slit i90 formed the tht-rough a, longitudinal sleeve tid.

is shown in Figure ld, a similar lever is situated at the opposite sideof the sleeve i and is carried by a hook $92, which is rigidly connected with the casing i515. The biiurceted end tilt of the lever |9|surrounds a bolt tijd, which is also carried by the casing HE. The boitis also provided with a coiied spring, which is not shown in thedrawings.

Due to the provision of the springs im, the levers 36 and di maintainthe tube it the position shown in Figure 12. Since the tube itil isconnected with the end 552 of the heating rod by the casing |60, thesleeve |51 and the block the resistance |50 will be always maintained.in close contact with the block 655. @the-reuse, slight movements orcontractions of the lc stance 55 or the block E55 might cause an'interruption of the electrical current between the reslstance |50 andthe block |55.

The cylindrical casing |69 is rigidly connected with two rings and |96,which are in contact with rollers |97, |99 and |99 (Figures 'l' and 8).The roller |91 is pivotally mounted in a support 20c, while the roller|98 is pivotally mounted in a support 20|. The roller |99 is carried bythe support 202. The fourth roller and its are not shown in thedrawings. The sup-port 2555 is carried by the foundation 203, while thesupports 20| and 202 are carried by. the foundation 204.

The cylindrical casing |69 is rigidly connected with an annular gear205, which meshes with e. pinion 206 rigidly connected with a gear wheel251 and rotatably mounted in the support 203, The gear wheel 201 mesheswith a gear 208, which is driven by a motor 209 resting upon the support2| 0. The motor is provided with a switch '2i i, which may be used forreversing at periodic intervals the direction of rotation of the motorand thus reversing the direction of rotation of the casing |99. Theswitch 2|| is also used for varying the speed of rotation of the motor209.

As shown in Figures 7 and 9, the jacket |04, which surrounds the casing|58 is carried by a.

frame 2|2 by means of members 2|3 and 2H.

'Ihe frame 2|2 is slidable in the vertical direction in two guidemembers 2|5 and 2|5, which are rigidly connected with and supported by acarriage 2|1.

The frame 2|2 rests upon cams 2|,8 and 2|9, which are keyed upon an axle220, rotatably mounted in the guides 2|5 and 2|6. A wheel 22|.

is also keyed upon the shaft 220 and is provided with a handle 222,which is used forrotating the cams 2|8 and 2|9. The carriage 2|6 ismounted on wheels 223 and 224 which are movable along rails and 22d.

yThe cams 2id and 2|9 are operated and the carriage till is moved alongthe rails 5225 and 226, when it is necessary to take the heating elementi550 out of the furnace.

'in operation, the terminals |55 andt are connected to a source ofelectrical energy, which isy not shown in the drawings. Then currentwill flow through the terminal 59, the block 50, the resistance 50, theblock |55, the tune 55| and the rnginal it. Y

l? on. the motor 209 is started, itwiil revolve the ca "ng through themedium of, the gear wheels 56, and 205. switch 2|3 is used to the speedof rota. on of the casingiii an reverse the direction of its rotation.

The turna :illustrated in Figures idonei i'l ci' the is used formanufacturing articles having a comparatively large tilametcr and/orhaving walls of diierent thicknesses. l .ce comprisesy an electr-iesistance 250, which is in :ranged parallel to the Ihngitudi mace. Theresistance d50 had and 252. 'vity formed in cylindrical plate or supportE53, which is made of amor" phone carbon. The opposite end 252 of theresistance is carried by a plate which also consists ci amorphouscarbon. The support 253 is surrounded by und connected with e. casingl255, is rigidly connected with a plate 255, as in ure l5.

plate surrounds and is rigidly connected with one end or a shaft25'i,which carries its `oppcsite end a terminal 258 adapted to he connected.to a source of electrical energy not shown. the drawings. The shaft 251is rotatably mounte in a bearing 259, which is electrically insulatedfrom its support 250 by a layer of insuletinn i. A. lange 252 isconnected with -o and surrounds a portion of the The end. iltit le uitudrawings, plate 254| is surrounded on three sides by a casing which isrigidly connected with e. plate The plate 264 is rigidly connected withone end of a shaft 265, the opposite end of which carries a terminal266, which may Eze connected to the source of electrical energy.

,graphite n more clearly in Figure i6 of thethis shaft. However, thegear wheel 21| is electrically insulated from the shaft 251 through theprovision oi' the insulation 212, which is interposed between the gearwheel 21| and the shaft 251.

'I'he gear wheel 21| meshes withfa gear wheel 213, which is keyed on ashaft 214 extending practically along the entire length of the furnace.'I'he shaft 214 -is supported by a bearing 215 forming a part of thesupport 215 and is also supported by a bearing 211, which forms a-partof the support 21|a.

The shaft 214 also carries a gear wheel 218, which is keyed to theyshaft 214 and which meshes with a gear wheel 219, ke'yed to the shaft255. However, the gear wheel 219 is electrically insulated from theshaft 235'through the provision of the insulation 288.

Due to the fact that the shaft 214 rotates at the same speed as thewheels 213 and 218, the two shafts 251 and 255 are rotated insynchronism with each other. The purpose of the shaft 214 and of thegear mechanism connected with this shaft is to provide for a synchronousrotation of the two shafts 251 and 255.

A motor 28|, shown in Figure 16, is used for driving the shafts 255 and251. 'Ihe shaft 282 oi the motor 28| rotates a roller or wheel 283,

which in its turn drives the disc or wheel 284.

The wheel 284 is rigidly connected with a worm 285. The gear wheel 259meshes with the worm 288 and is driven by it. Since the sleeve 251 iscast of the same piece as the gear wheels 288 and 259, the gear 258 willbe rotated along with the sleeve `251 when the gear 258 is rotated bythe worm 285.

The gear wheel 258 meshes with the pinion 285, which is carried by ashaft 281 supported by the walls 288 and 289 (Figure 16). The pinion 285meshes with a gear 298 carried by a shaft 29|a, i i which is rotatablymounted in the wall 288. The

gear wheel 298 drives the toothed wheel 29|, which is keyed to the shaft285.

In order to prevent the leakage of the electrical current, a part of thesleeve 251 and of the gear wheels 289 and 288 consists of the electricalinsulation 292. At least a part of the Wheel 29| also consists of theinsulation 293. The wall 288, which is used as a support for the gearwheels 285 and 298, is also provided with insulation 294 surrounding theshaft 255.

As has beenmentioned already, the motor 28| drives the shaft 282, whichrotates the Wheel 283. A suitable device 295 is used for shifting theposition of the wheel 283 with respect to the wheel 284 to change thespeed ofrotation of the latter or to disconnect .the wheel 283 from thewheel 284. The wheel 284 drives the worm 285, which in its turn rotatesthe gear wheels 258 and 288. The gear wheel 258 drives the pinion 283,which transmits its rotation to the gear 288. The gear 298 drives thegear 29|, which is keyed to the shaft 255. Due to this arrangement, theshaft 285 is driven by the motor 28|.

'I'he shaft 285 drives by means of the gears 213 and 218 the shaft 214.which rotates the gears 213 and 21| and thus drives the shaft 251. Theshafts 285 and 251 rotate in synchronism with each other and drive theblocks 254 and 283, which carry the electrical heating resistance 258,so that the electrical resistance 258 is rotated within the casing 298.

The walls 288 and 288 are rigidly connected with and surrounded by themain cylindrical casing or container 295. The casing 295 may be drivenindependently of the resistance 258 by a separate motor 291, providedwith a switch 3|8 for varying the speed of the motor (Fig l5) The casing295 is rigidly connected with a toothed ring 298, which meshes with agear wheel 299 rigidly connected with a gear wheel 388 and rotatablymounted in a support 38|. The casing 298 is also rigidly connected withrings 3|| and 3|2 which are supported by rollers 3|3, 3|4 and 3|5mounted in supports 3|5, 3|1 and 3|8. (Figs. 15V and 17.)

The gear wheel 388 meshes with a gear wheel 382, which is rigidlyconnected with the shaft f of the motor 291.

The rotation of the motor 291 is transmitted through the gear wheels382, 388, and 299 to the toothed ring 298 and to the cylindrical casing298. Since the walls 288 and .289 are rigidly connected with the casing295, these walls together with the pinions 285 and 298 will rotate alongwith the casing 295. The relative movement of the pinion 298 withrespect to the gear wheel 29| will not interfere with the rotation ofthe latter, which is caused by the motor 28|. However, only one of themotors 28| and 291 may be operated at one time, since it is notnecessary to use both motors simultaneously.

When both the motor 28| and the motor 291 are used, the casing 298 willbe rotated with a velocity which is independent of the velocity ofrotation of the resistance 258 within the casing 298.

The furnace illustrated in Figures 18 to 22 of the drawings is heated bya three-phase elece trical current. The heating element designatedgenerally by the numeral 325 consists of three interconnected rods 328,321, and 328, which are adapted to be placed above the fusible material329. The graphite rods 328 and 321 are parallel to each other and may beplaced horizontally above the fusible material 329. As shown in Figure22, the forward ends 338 and 33| of the rods 325 and 321, respectively,are rounded and have a smaller cross-section than the main body of theserods.

The adjacent end 332 of the carbon rod 328 is provided with screwthreads. The rod 328 is inclined with respect to the rods 328 and 321,as shown in Figures 18 and 19 and it is placed in such a way that itsthreaded `end 332 is sitr 328, 321, and 328 are supported by threecarbon blocks 335, 338, and 331. The block 338 has a hollow cylindricalportion which is provided with inner screw threads 338 and carries asleeve 338 having a cavity, in which lies the rounded end 348 of the rod328 (Fig. 21).

The block 335 is provided with a hollow cylindrical V portion havinginner screw threads 33|, and a sleeve 342 is screwed into the block 331.The threaded end 343 of the inclined rod 328 is screwed into the sleeve342, as shown in Figure 21. The adjacent end of the rod 321 which isparallel to the rod 328, is carried by a. sleeve which is not shown inthe drawings and which is similar to the sleeve 339.

yThe block sas is insulated from the mock 331 .331 from the block 335,while the block 335 is insulated from the block 336 by the insulatingwall 346. i

The insulating wall 344 has a portion 341, which projects beyond theblocks 336and 331 and which separates a metallic conductor 348 from ametallic conductor 349. A projecting portion 350 of the insulating wall346 and a similar projecting portion 35i of the insulating wall 345 aresituated at both ends of the metallic conductor 352. The metallicconductors 348, 349, and 352 may be connected with the three phases of agenerator or a main, which is not 'shown 4in the drawings and whichsupplies a three-phase electrical current.

The insulating members 341, 350, and35l along with the metallicconductors 348, 349, and 352 are surrounded by a sieeve which is made ofan insulating material. 353 is surrounded in its turn by a metalliccasing 354.

The casing 354 is made of one piece with the flange 385, which isprovided with a glaphited packing ring 355. The casing also carries apair of pivots 356, only one of which is shown in the drawings.'The-pivots are carried by a pairy of supports and t, which areinterconnected loy a platicrr Si. The platform 359 andthe two supportsits and ioim a carriage, which is mounted on wheels Stil and 35i and ismovable along the rail The main container t oi the -iuinzuze is rigidlyconnected with two covers itil and 5365i, as shown in Figure i8. Thecovers Cite and 355 and the container or casing 363 surround a heatinsulating lining 35 and a ceramic layer 35T. The central opening Z338formed in the cover 355 serves for the insertion oi' the heating element325.

In the .position shown in Figures i8 and 21, the 4packing 355 of the inge is in contact with the rotating cover and thus prevents the escapeof gases Athrough the opening The central charging cpeniformed in thecover fitti at the opposite end ci' the furnace is closed by ameinberiie, which ls provided with a handle 315. The member diie ismovable along the guides 3H.

A pair of rings 312 .and 313 are rigidly connected with the container363 and are supported by the rollers 313 and S'ii, which are rotatablymounted in the supports E15 and 311. The foundation 313 serves as acarrier for the supports .tit and 311. An annular gear 31S is rigidlyconnected with the casing 363 and meshes with a gear wheel 383 mountedin the support 38E. A motor 333 is used for driving the gear wheel 38,2which meshes with the wheel litt.

As shown in Figure 19, the heating element 325 may be raised verticallywhen it is not in use and may be protected by a covering 364, which isshown in cross-section in Figure 19.

- In operation, the metallic terminals 348, 339

and 352 are jointed to a generator of a threephase current so that thiscurrent will flow through the blocks 335, 336, and 331, and through thesleeves 33S, 3&2l and the third sleeve, whichy is not shown in thedrawings. The current passing through these sleeves will flow throughthree rods 326, 321, and 328 to the neutral point formed by the plate333.

The insulating sleeve What is lclaimed is:

1. In combination, .a cylindrical container, means situated outside ofsaid container for supporting the same, a heatingv rod at least partlywithin said container, a pair of large plates situated outside of saidcontainer and close to two lends thereof, means connected with one ofsaid large plates for supporting one end of said heating rod, meansconnected with the other large plate for supporting the other end ofsaid heating rod, a space being formed within said container betweensaid heating rod and the walls thereof, means connected with said largeplates for supplying an electrical current to said heating rod, meansfor producing a flow of gas within said container, means connecting thefourth-mentioned means with the fifth-mentioned means, rings situated inthe path of said flow of gas at two ends of said container andsurrounding said heating rod, and means lconnected with thefourth-mentioned means and-carryingsaid rings.

2. In combination, a container, means connected with lthe exteriorsurfaces of said container for supporting the saine, a heating rod atleast partly within said container, a free space being provided withinsaid container around said heating rod, two large plates situatedoutside of said container and at the two ends thereof, means connectedwith said large plates for supporting two ends of said heating rod,means connected with said large plates for transmitting an electricalcurrent to said heating rod, means connected with the thirdnientionedmeans for providing a iiow of gas within said container, at least onering situated in the path of said dow of gas, sleeve carrying said ringand surrounding a poru tion of said heating rod, and means connectingsaid sleeve with the third-mentioned means.

3. In combination, a container, means for sunportng said container, aheating rod, means supporti-ng said heating rod at least partly withinsaid container, a free space being formed within said container aroundsaid heating rod, and means situated on opposite sides of'said containerand adapted tocreate a uniform alternating flow of gas through saidcontainer in two opposite directions.

e. In combination, a container, a heating rod, means supporting'saidheating rod at least partly Within said container, means connected, withthe first-mentioned means for supplying an electrical current to saidheating rod, rollers situated outside of said container and supporting4the same, shafts upon which said rollers are mounted, and pivotingmembers carrying said shafts and adapted to adjust the level of saidIrollers and their relative distances.

5. In combination, a rotatable cylindrical container, a heating rod, atleast a part of which is situated Within saidcontainer, two-large platessituated outside of said container at the two ends thereof, meansconnected with said large plates and supporting the two ends of saidheating rod, means connected with said large plates for supplying anelectrical current to said heating rod, means connected with thesecond-mentioned means for moving one of said large plates with respectto said container, a fan, means connecting said fan with thesecond-mentioned means, and a movable rod supported by thesecondmentioned means and adapted to come in contact with said heatingrod to clamp the same.

v6. In combination, a container, a heating rod, at least a part of saidheating rod consisting of a carbonaceous material being situated withinclose tots'aid container, means connecting said plate with said graphitemember, a casing surrounding said plate, a sleeve surrounding a portionof said heating rod adjacent tor said end thereof, means connecting'said sleeve with said casing, and means adapted to be connected to a'source of electrical energyand supporting the opposite end of saidheating rod.

7. In combination. a cylindrical container, means situated outside ofsaid container for supporting the same, a heating rod at least partlywithin said container, a pair of plates situated outside of saidcontainer and close to the two ends thereof, means connected with one ofsaid plates for supporting one end oi said heating rod, means connectedwith theA other plate for supporting the other end of said heating rod,a space being formed within said container between said heating rod andthe walls thereof, means connected with said plates for supplying anelectrical current to said heating rod, means for producing a iiow ofgas within said container, means connecting the fourth-mentioned meanswith the fifth-mentioned means, rings situated at two ends of saidcontainer and surrounding said heating rod, means connected with thefourth-mentioned means and carrying said rings, other rings having alarger diameter than the mst-mentioned rings and situated within saidcontainer at two said ends thereof, and means connecting thelast-mentioned rings with said container. said gas flowing between thefirstmentioned rings and the second-mentioned rings.

8. In combination, a container, means connected with the exteriorsurface of said conaosaoaa tainer for supporting the same, a heating rodat least partly within said container, a free space being providedwithin said container around said heating rod, two large plates situatedoutside of said container `and at the two ends thereof, means connectedwith said large plates for supporting two ends of said heating rod,means connected with said large plates for transmitting an electricalcurrent to said heating rod,

i means connected with the third-mentioned means for providing a flow ofgas within said container, a ring, a sleeve carrying said ring andsurrounding a'portion of said heating rod, means connecting said sleevewith the third-mentioned means, another ring having an inner diameterwhich is larger than the outer diameter of said ring, and meansconnected with said container and the second-mentioned ring andsupporting the second-mentioned ring within' said container, said gasflowing between the flrst-mentione ring and the second-mentioned ring. i9. In combination, a rotatable cylindrical container, a heating rod, atleast a part of which is situated within said container, two largeplates situated outside of said container at the two ends thereof, meansconnected with said large plates and supporting the two ends of saidheating rod, means connected with said large plates for supplying anelectrical current to said heating rod,

means connected with the second-mentioned -1 means for moving one ofsaid large plates relatively to said container, and a rod adapted tocontact said heating rod to clamp the same and to interrupt said contactwhile an electrical current is supplied to said rod, thesecond-mentioned means comprising means for movably supporting thelast-mentioned rod.

:HENRI GEORGE.

GASTON DELPECH.

